LECAX-OBA.] LECANO-LECTDEEI. 477 



S.W. Ireland. B. M. : Fingle Bridge, near Chagford, S. Devon ; Dol- 

 gelly and Rhiwgreidden, Merionethshire ; Bettwys-y-coed, Denbighshire ; 

 Island of Anglesea ; Wrekin Hill, Shropshire ; Eglestone, Durham ; 

 Staveley, Kend'al, Westmoreland ; Lamplugh, Cumberland. King's Park, 

 Edinburgh; Ben Lawers and Craig Tulloch, Perthshire; Glen Callater 

 and Morrone, Braemar, Aberdeenshire. Crogham and Mangerton, co. 

 Kerry. 



Form atrata Cromb. Grevillea, xix. (1891) p. 58. Thallus only 

 here and there sparingly visible upon the predominating hypothallus. 

 Apothecia scattered, minute. Gyalecta atrata Ach. Vet. Ak. Handl. 

 1808, p. 229. 



A rudimentary, though apparently permanent condition in which 

 scanty traces of a ferruginous thallus are seen only around the apothecia, 

 which in the British specimens are numerous. 



Hab. On quartzose rocks in an alpine locality. Distr. Only very 

 sparingly on one of the N. Grampians, Scotland. B. M. : Morrone, 

 Braemar, Aberdeenshire. 



176. L. lacustris Fr. fil. Yet. Akad. Hand], vii. (1867) p. 24. 

 Thallus determinate or subeffuse, thin, smooth, rimuloso-diffract, 

 pale testaceous or ochraceous (K , CaCl ). Apothecia minute, 

 uroeolato-innate, reddish testaceous or brownish ; the thalline 

 margin tumid or usually little distinct ; spores 8nae, ellipsoid, 0,013- 

 18 mm. long, 0,006-9 mm. thick ; paraphyses not discrete, slightly 

 brownish or yellowish at the apices ; hypothecium colourless ; 

 hymenial gelatine bluish, then sordid-wine-red or tawny with 

 iodine. Cromb. Grevillea, i. p. 172 ; Leight. Lich. Fl. ed. 3, p. 195 

 (excl. forma punctata). Lecanora cjibbosa forma lacustris Leight. 

 Lich. Fl. ed. i. p. 210 ; subsp. lacustris Cromb. Lich. Brit. p. 55. 

 Lichen lacustris With. Arr. ed. 3 (1796) iv. p. 21, t. 31. fig. 4. 

 Urceolana Acharii Gray, Nat. Arr. i. p. 457 ; Hook. Fl. Scot. ii. 

 p. 47 ; Sm. Eng. Fl. v. p. 172 ; Tayl. in Mack. Fl. Hib. ii. p. 132 

 (incl. var. /3). Licheii Acharii Westr. Eug. Bot. t. 1087. Aspicilia 

 epulotica Mudd, Man. p. 161 pro maxima parte. Brit. Exs.: Cromb. 

 n. 71. 



The thallus is normally pale, almost white, but is usually more or less 

 ochraceous from being tinged with peroxide of iron. It often spreads 

 extensively over the substratum and is at times semi-aquatic. The 

 apothecia, which are numerous and often crowded, are at first minute, 

 immersed, rarely at length prominent, occasionally in age becoming sub- 

 moderate, plane, and distinctly margined by the thallus. Occasionally 

 the spores are rather thicker, 6,012 mm., when it is Lecidea subepulotica 

 Nyl. Mem. Soc. Cherb. t. v, p. 337, a state which occurs also in Great 

 Britain and Ireland. Var. /3. cyrtaspis (Ach.) Cromb. Grevillea, xix. 

 p. 58, does not belong to this species (cfr. Fr. fil. Lich. Scand. p. 288). 



Hab, On rocks (often inundated) in streams in upland and subaipine 

 districts. Distr. Only here and there, though plentiful where it occurs, in 

 Great Britain and Ireland. B. M. : Lyndhiu^t Moor, New Forest, Hants ; 

 Dartmoor, Devonshire ; Withiel, Cornwall ; Nannau, Dolgelly, and near 



